<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
  <style>
    * {
      box-sizing: border-box;
    }
    .wrap {
      display: flex;
      width: 800px;
      height: 400px;
      border: 1px solid gray;
      flex-direction: row;
      flex-wrap: wrap;
      justify-content: space-around;
      align-items: center;
    }
    .div {
      width: 100px;
      height: 100px;
      background-color: red;
    }
    .t1 {
      order: 0;
    }
    .t2{
      order: 2;
    }
    .t3 {
      order: 1;
    }
  </style>
</head>
<body>
  <div class="wrap">
    <div class="div t1">
      1
    </div>
    <div class="div t2">
      2
    </div>
    <div class="div t3">
      3
    </div>
  </div>
</body>
</html>